Novak Conversions Jeep Wrangler TJ radiator

PCM or transmission?

Cmwilliams32294

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Dec 11, 2025
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South west Florida
I have a 2005 tj 4.0 auto with 149k miles im having an issue when trying to take off from a stop and sometimes seems to get stuck in 2nd gear and shudders/shakes my dash. I’ve replaced filter and fluid didnt smell burnt or dark. Still having the issue now if I floor it to pass someone it gets hung up until I let go of throttle and re apply. I’ve had limp mode a few time now always clears and gos back to how it was before limp mode after I pull over and shut it down

Is this the pcm or transmission related

Also seems to only do it after transmission is warm

And also my fuel mileage has seemed to tank I only get like 240 miles out of a full tank
 
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@Cmwilliams32294 How is your shifting from 1st to 2nd in the morning? Do you have any codes? You can call me at 866-888-7710 to discuss in further detail if you'd like.

Thanks,

Mark
 
@Cmwilliams32294 How is your shifting from 1st to 2nd in the morning? Do you have any codes? You can call me at 866-888-7710 to discuss in further detail if you'd like.

Thanks,

Mark

Sometimes it shifts a little weird in the morning and sometimes normal I have got the p0732 , p1776 and p0700 code the only one that has come back is the p0700 code usually when it goes into limp mode
 
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Sometimes it shifts a little weird in the morning and sometimes normal I have got the p0732 , p1776 and p0700 code the only one that has come back is the p0700 code usually when it goes into limp mode

The occasional hard shift from 1st to 2nd is the transmission control module side of the computer failing you. It does not happen all the time usually twice until up to operating temperature. The P1776 and P0732 are also in your computer. The p0700 code is a result of the other two 700 codes.
 
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The occasional hard shift from 1st to 2nd is the transmission control module side of the computer failing you. It does not happen all the time usually twice until up to operating temperature. The P1776 and P0732 are also in your computer. The p0700 code is a result of the other two 700 codes.

So the computer is causing it to get stuck in a gear ? And causing what feels like shuddering when accelerating from a stop? Not the torque converter itself
 
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So the computer is causing it to get stuck in a gear ? And causing what feels like shuddering when accelerating from a stop? Not the torque converter itself

I had the same issue. Just some of the fun 2005-06 electric issues. :)

Bottom line: Yeah @Wranglerfix is the solution. It is the most affordable, and ONLY quality option. Seriously, like the amount of people dropping 1-2k on a PCM that fails out of the box is wild. Mark is awesome and picked up the phone when i called at like 6:30 after I got off of work. The PCM fixed that same trans issue in mine, as well as helped my jeep just run smoother overall. It shifts BETTER than when I first got it and I haven't had a single CEL since. One of the best investments I've made in my jeep.
 
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I had the same issue. Just some of the fun 2005-06 electric issues. :)

Bottom line: Yeah @Wranglerfix is the solution. It is the most affordable, and ONLY quality option. Seriously, like the amount of people dropping 1-2k on a PCM that fails out of the box is wild. Mark is awesome and picked up the phone when i called at like 6:30 after I got off of work. The PCM fixed that same trans issue in mine, as well as helped my jeep just run smoother overall. It shifts BETTER than when I first got it and I haven't had a single CEL since. One of the best investments I've made in my jeep.
I hope this will be the cure for mine too I’d rather not have to drop the tranny if I don’t have to lol
 
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I bought the wranglerfix pcm and seems to run smoother. It gave me p0016 code after a few minutes of running the old computer didnt find that code. Code went away after rotating Opda CC a tad. Took her around the block and seemed peppier the real test will be tomorrow on my commute to and from work
 
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Well the pcm did NOT fix my transmission issue. Still shuddering when taking off after it’s warmed up

Long message but bear with me:

Sorry to hear that man. Still a good investment though, believe me I'll explain: When the PCM fixed my issue, I had already changed several sensors prior that, which I believe helped. Installed PCM early June. Right after the PCM upgrade, I messed up some wiring on an ignition coil rail replacement, causing a bad misfire, rough idle. It still had the rough shift in the mornings as well. I had a shop go through my engine bay and fix the wiring/grounds and fixed the ignition coil wiring. ($100 coil rail upgrade attempt that fried the rail, turning into a $600 shop fix lol) After this, I have had ZERO issues.

Here is the list of things I did IN ORDER for chasing the shifting and poor running issue:

-Crank position sensor (big one, possible p0016)
-Cam position sensor (big one, will send vehicle into limp mode above 2500 rpms, also possible p0016)
-Throttle position sensor (better idle and could be a limp mode culprit though not as likely)
-Wrangler Fix PCM (big and corrected the limp mode in combination with the sensors, and doesn't have the same pitfalls of the stock PCM)
-New NGK Ignition coil rail/the shop visit, which resoldered and re-grounded the ignition coil rail, as well as checked all the engine wiring. (Zero shifting/shuddering issues after this and ran better than ever)


ALL OF THIS TO SAY: You could have some bad wiring or sensors. They all work in conjunction and if one senor is failing, it can cause others to go with it given the year and age. I am by NO MEANS qualified to speak on this but that was just my experience. I bought the shift solenoid and never had to install it actually. So new sensors in conjunction with the PCM and good wiring was the golden ticket. Jeep runs great and has given me zero problems.
 
The pcm did fix the shaky mirrors and poor idle and shift points seem better. The p0016 code I fixed by adjusting the Opda the only codes now are p0700 and p0720. Im going to change out the output speed sensor and transmission mount and see what that does before anything with dropping the transmission
 
So I put the jeep on 4 jack stands and put in neutral and revels it a bit and the rear wheels moved slowly forward every time I gave it throttle. Also was hard to stop the rear wheels when I put it in reverse almost had to stand on the pedal to get them to stop. My brakes are good
 
Novak Conversions Jeep Wrangler TJ radiator